Internal work light

ABSTRACT

A sealed fluorescent tube light that can be connected to other similar units to form a string of work lights. The tube light locates and seals the ballast and starter inside of its interior so as to provide compactness and safety during use. A radio frequency interference shield is provided around the tube light to prevent the radiation of electrical interference from the electrical components.

United States Patent [72] Inventor Graydon A. Phlieger,Jr.

325 McLeod Ave., Coca, Fla. 32922 [21] AppLNo. 752,729 [22] Filed Aug.5,1968 [45] Patented Feb.16,l971

[54] INTERNAL WORK LIGHT 3 Claims, 6 Drawing Figs. [52] U.S.C1240/51.l1, 240/11.2,240/11.4, 313/22 [51] 1nt.CI ..H05b33/04 [50]FieldofSearch 240/51.11, 11.4, 11.2E.V., 9, 26; 313/22 (Inquired) 56}References Cited UNITED STATES PATENTS 1,954,915 4/1934 Bouwers3l3/22(X) 2,336,750 12/1943 Roneyetal 240/51.11(X) 2,347,174 4/1944Crossetal..... 240/51.1l(X) 2,413,599 12/1946 Beck 240/51.11(X)2,525,013 10/1950 Baumgartner 240/1l.4

Primary Examiner-John M. Horan AssistantExaminer-Robert P. GreinerAttorneys-James O. Harrell and G. T. McCoy ABSTRACT: A sealedfluorescent tube light that can be connected to other similar units toform a string of work lights. The tube light locates and seals theballast and starter inside of its interior so as to provide compactnessand safety during use. A radio frequency interference shield is providedaround the tube light to prevent the radiation of electricalinterference from the electrical components.

PATENTF D FEB. 5197:

sum 2 [1F 3 5a i I Q 7 i if 1 P In 0 1- w E E" o I g"? FIG. 4

INVENTOR.

GRAYDON A. PHLIEGER, JR.

ATTORNEYS PAT TEU FEB? 6 IS?! SHEET 3 0F 3 INVENTOR. GRAYDON A. PHLIEGERJR.

ATTORNEYS INTERNAL WORK LIGHT The invention described herein was made byan employee of the United States Government and may be manufactured andused by or for the Government for governmental purposes without thepayment of any royalties thereon or therefor.

This invention relates generally to a fluorescent light fixture and,more particularly, to such a light fixture wherein all components arehoused within tube light units.

The construction, maintenance and modification of space vehicles andlaunch vehicles necessarily requires that activities take place withinthe vehicles themselves and there normally is insufficient lighting toadequately perform-these functions within the vehicles. Furthermore,existing light fixtures require the use of individual extension cordswhich results in a mass of tangled and crossed electrical conduits whenit is necessary to utilize several such light fixtures. It has also beenknown to mold the ballast for a fluorescent light into a cord connectedwith the light fixture itself. These devices necessarily have thedisadvantage of wearing and deteriorating to the extent they becomehazardous. Although light fixtures have been connected in a string toprovide a long light source, it has not been possible to individuallyfuse the lamps. Another disadvantage of the known lamp fixtures has beenthe inability to completely house all of the elements within a singleunit and thereby avoid any hazardous sparks or electrical shocks thatmight cause fires or explosions in the hazardous environment existing ina space vehicle.

In order to overcome the disadvantages of the prior art, the instantinvention contemplates a light fixture including a tubular member whichhouses all of the light unit elements and seals them to the ambientenvironment by utilizing end caps having fittings thereon for receivingelectrical conduits and purge gas fittings. 7

It is an object of the instant invention to provide a fluorescent lightdevice that can be connected to similar units to form a light string.

Another object of this invention is to provide a fluorescent lightfixture that completely houses the elements necessary for operationwithin each tube light unit to thereby provide a strong and easilymaintained light source without encountering unduly hazardousconditions.

Still another object of the instant invention is to provide several tubelights interconnected with one another while maintaining electricallyparallel operation of each light as well as permitting the individualtube lights to be purged with dry nitrogen to prevent hazardous gasesfrom leaking into the lights and causing an explosion.

A still further object of this invention is to provide a tube lighthaving a substantially tubular member sealed by end caps and withinwhich a fluorescent bulb and all electrical elements are mounted toprovide a substantially hazard free lighting fixture.

Still another object of the instant invention is to provide a tubularmember having end caps for tightly sealing the interior of the tubularmember with a fluorescent bulb and a chassis mounted within tubularmember to support a portion of the electrical elements and havingsupports in the tubular member for mounting the chassis and bulb.

A still further object of this invention is to provide a tube lighthaving a substantially light transparent tubular member having end capssealing the interior thereof and which utilizes a chassis mounted on oneend cap and attached to a stabilizer plate mounted on electricallyconductive rods with a second stabilizer plate at the opposite end ofthe rods to permit mounting of a fluorescent bulb between the stabilizerplates and interior of the electrically conductive rods with a ballastand starter socket mounted on the chassis and having electrical conduitsentering the tubular member through the end caps and connected with theelectrical elements housed within the tubular member to permitend-to-end connection of a plurality of tube lights while maintainingelectrically parallel operation of each light and also including purgegas fittings through each end cap such that the string of lights may bepurged with an inert gas to prevent hazardous gases from leaking intothe lights and causing an explosion.

Still another object of the instant invention is to provide a tube lighthaving a substantially light transparent tubular member having end capssealing the interior thereof with stabilizer plates adjacent oppositeends of the tube to permit mounting of a fluorescent bulb between thestabilizer plates and inwardly of a plurality of rods extending throughthe end caps with a chassis having a ballast and starter attachedthereto and mounted on a pair of the rods and having electrical conduitsentering the tubular member through the end caps and connected with theelectrical elements housed within the tubular member to permitend-to-end connection of a plurality of tube lights while maintainingelectrically parallel operation of each light and also including purgegas fittings through each end cap such that the string of lights may bepurged with an inert gas to prevent hazardous gases from leaking intothe lights and causing an explosion.

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily apparent as the same becomes betterunderstood by reference to the following description when considered inconnection with the accompanying drawings wherein:

FIG. 1 is a top sectional view of a portion of the instant inventivetube light;

FIG. 2 is an elevationalsectional view of the tube light partially shownin FIG. 1;

FIG. 3 is an electrical schematic of the circuitry utilized in the tubelight shown in FIGS. 1 and 2;

FIG. 4 is a partial top sectional view of one end of the tube light ofFIG. 1 showing the wiring arrangement for operation of the instantinvention;

FIG. 5 is an elevational partial sectional view of an alternativeembodiment of the tube light of FIGS. 1-4; and

FIG. 6 is an electrical schematic of the circuitry utilized in thetubelight shown in FIG. 5.

Referring now to the drawings, and more particularly to FIGS. 1 and 2,wherein tube light 10 is shown to include one end cap 12 and a secondend cap 14 that are attached to a substantially light transparentplexiglas tube 16 by threads I8. Grooves 20, see FIG. 2, may be providedin end caps 12 and 14 for a purpose to be more fully understoodhereinafter. End cap 12 has central aperture 22 and apertures 26 whichprovide access for rivets 32 to fixedly attach retainer plate 28. endcap 12, and chassis 30 to one another.

Chassis 30 includes longer upright flange 34 and shorter upright flange38 extending from body 36. Flange 34 attaches to end cap 12 by rivet 32.Ballast 40 and starter socket 42 are rigidly secured to body 36 ofchassis 30 and are supported thereby. Starter 44 is mounted in socket42. Starter socket 42 and ballast 40 are attached to chassis body 36 byconventional devices.

Bipin lamp holders 54 are connected to a pair of stabilizer plates 50,slightly less in diameter than the inner diameter of tube 16, by nutsand bolts 56. One stabilizer plate 50 is secured to shorter uprightflange 38 by bolts 52 to thereby provide a rigid connection between thatstabilizer plate 50, chassis 30, and end cap 12.

Three longitudinal, electrically conductive rods 58 have heat shrinkabletubing 60 substantially covering their length between stabilizer plates50. Threads 62 on the ends of rods 58 receive nuts 64 to securely andfixedly attach stabilizer plates 50 to one another and to chassis 30 asnoted hereinabove. Fluorescent tube 66 is mounted in bipin lamp holders54 to complete the inner structure of tube light 10.

A radio frequency interference (RFI) shield 88 having an outer diametersubstantially equal to the inner diameter of tube 16 may be utilizedwithin tube 16 and surrounding the hereinabove described internalstructure of tube light 10. Alternatively, RFI shield 88 could be ofslightly greater diameter than the external diameter of tube 16 and heldin place by grooves 20 in end caps 12 and 14. This construction preventsradiation of radio frequency interference which is created byfluorescent lamps and which would otherwise cause discrepancies in theelectronic recording and other equipment utilized in the vicinity ofspace vehicles where tube lights 10 may be used.

As best seen FIG. 2, floating end ring 70 fits around and is slidable onend cap 12. Fixed end ring 72 fits on end cap 14 by a threadedengagement with bulkhead connector 78. Fixed end ring 72 has chain 74attached thereto with receptacle protection cap 76 attached to the endof chain 74 to provide an easily and readily accessible protector forconnector 78 when the latter is not in use.

Referring now to FIGS. 3 and 4, electrical conductor 80, leading from anelectrical power source, not shown, into and through aperture 22 in endcap 12 is composed of three wires, green wire 82 which extends to one ofthe rods 58, black wire 84 which extends to a second of the three rods58, and a white wire 86 which comes from conduit 80 and connects withthe third rod 8. It is to be understood that a conventional bulkheadconnector, such as 78 in end cap 14, could be utilized in end cap 12instead of extending conductor 80 therethrough. Each of the wires 82, 84and 86 may be provided with terminal lugs 90 for rapid and easyconnection to rods 58 by nut 64. Green wire 92 and black wire 94 leadfrom their respective rods 58 to connect with ballast 40 on chassis 30and white wire 96 leads from lamp socket 54 to ballast 40. White wire 98leads from lamp socket 54 to starter socket 42 and white wire 100 leadsfrom lamp socket 54, shown in FIG. 4, to the lamp socket at the oppositeend of rods 58 and bulb 66. A slow blow fuse 102, FIG. 4, is inserted inthe circuitry and attached to end cap 14 to prevent overload of theelectrical circuitry and the existence of hazardous conditions.

Referring again to FIG. 2, purge gas fittings 104 extend through endcaps 12 and 14 and permit connection of purge gas conduits 106 tothereby permit purge gas, such as dry nitrogen, to flow into theinterior of tube 16 and thereby provide an inert ambient environment forthe electrical system of the tube light 10. It is to be understood thatconduits 106, as do conduits 80, extend from some conventional source,not shown, into a first tube light 10 and from that tube light to thenext tube light 10 in the string. Such system may be continued to theextent desired with observance of electrical principles to preventoverload of any power system or circuitry being used to operate thesystem.

As best seen in FIG. 2, lanyard 48 may be attached to and extend betweenfloating end ring 70 and fixed end ring 72 to provide for suspension oftube light 10 in any given work area.

Referring now to FIGS. and 6 wherein alternative embodiment of tubelight is designated by the numeral 110. Tube light 110 includes end caps112 and 114 at respectively opposite ends of plexiglas tube 116. Eachend cap 112 and 114 includes base member 120 having a central aperture122 for a purpose to be more fully understood hereinafter. Three spacedapertures extend through base 120 slightly inwardly of the projecteddiameter of plexiglas tube 116. Flanges 126 extend toward one anotherfrom each of the end caps 112 and 114 and are provided with grooves 128for receiving seal 118 as will be more fully understood hereinafter.

Three rods 158 of slightly greater length than tube 116 extend betweenand through end caps 112 and 114 and are secured thereto by conventionalnuts mounted on the threaded ends of rods 158.

Chassis 130 is mounted between a pair of rods 158 as by welding at 132to provide a rigid base for receiving ballast 140 and starter 144.

Mounted inwardly ofend plates 112 and 114 is a pair of stabilizer plates150 of a diameter less than the internal diameter of tube 116. Threenotches equally spaced about the periphery of stabilizer plates 150permit accurate location of the stabilizer plates in the vicinity ofrods 158. Apertures with insulators 156 in stabilizer plates 150 areutilized to permit the wiring, to be described more fully hereinafter,to pass therethrough and extend through tube light 110. Bipinlampholders 154 are mounted interiorly or centrally of stabilizer plates150 to permit mounting of conventional fluorescent tube 166 therebetweenand establish the source oflight.

Each end plate 112 and 114 is provided, in apertures 122, with anelectrical connector 178 which is fixedly attached to base 120 byconventional means. These connectors permit rapid attachment ofelectrical leads form a power source to equipment and elements housedwithin tube 116. Conventional electrical wiring is connected in theinterior of tube 116 as is well-known and shown in the electricalschematic of FIG. 6. Wires 182, 184 and 186, neutral, ground and line,respec tively, extend from connectors 178 to the various elements withintube light 110. For example, the wires lead from one connector 178 tothe various elements and then along rods 158 to connector 178 at theother end of tube light 110. In order to prevent the wires from becomingoverheated or contacting fluorescent tube 166, they should be laced torods 158 with some material such as nylon lacing and preferably arelaced so as to be interiorly of rods 158. This construction permits rods158 to be relatively close to tube 116 and thus provide some support orstrength to tube 116 in the event tube light should be dropped orimpinged by some relatively sharp object.

By providing substantially rectangular bases on end caps 112 and 114with apertures in the corners thereof it is possible to rapidly connectlanyard 48, see FIG. 2, between end caps 112 and 114 to thereby provideamethod of hanging tube light 110 from the structure in the area wherework is to be done.

A conventional radio frequency interference shield 188 of a diameterslightlygreater than the external diameter of tube 116 is mountedthereover and-held in'place in groove 128 in flanges 126 of end caps 112and 114. Seals 118 function not only to assist in maintaining theinterior of tube light 110 airtight but also to locate and maintainshield 188 in its desired position. This location of the RFI screenprevents shorting of internal components and also affords some physicalprotection to the transparent tube against scratching and breaking. Inthe event tube 116 is broken, most of the pieces thereof would beretained within shield 188 and end caps 112 and 114 and thus preventedfrom falling into undesirable locations.

Tube light 110 is generally provided with purge gas fittings 204extending through end caps 112 and 114. This construction, as with tubelight 10, permits connection of a group of tube lights in a string witha purge gas system connected with a source of inert gas, not shown, tosubstantially eliminate hazardous conditions.

Thus it is seen that the instant invention provides alternativeembodiments of tubelights capable of end-to-end connection with powerbeing fed through while each operates electrically parallel with eachlamp individually fused to permit greater flexibility of suspension andutilization of a single or group of tube lights 10 or 110. These newtube lights can be used in hard to reach, unlighted areas wheremaintenance, assembly, or other operations might be performed. No partof tube lights 10 or 110 is molded unit thereby making it possible toeasily replace parts by disassembling a defective unit. Use of lanyards48 provides additional flexibility in the location of the tube lightswithin a given position.

Obviously many modifications and variations of the subject invention arepossible in light of the above teachings. it is therefore to beunderstood that, within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

I claim:

1. A tube light comprising:

a. a substantially light transparent tubular member;

b. end caps tightly sealing the interior of said tubular member;

c. a plurality of rods extending through said tubular member and saidend caps;

d. said plurality of rods having threaded ends receiving nuts forattaching said end caps to said tubular members;

e. a pair of stabilizer plates supported by said plurality of rods;

f. bulb sockets mounted on the opposite interior faces of I saidstabilizer plates for receiving a fluorescent bulb; g. electrical wiresinterconnecting said bulb sockets; h. a chassis mounted on saidplurality of rods; and

cuit operation of said tube light with other similarly connected tubelights.

3. A tube light as defined in claim 1 further comprising:

a. a radio frequency interference shield surrounding said transparenttubular member; and

b. said radio frequency interference shield being held in place by saidend caps.

1. A tube light comprising: a. a substantially light transparent tubularmember; b. end caps tightly sealing the interior of said tubular member;c. a plurality of rods extending through said tubular member and saidend caps; d. said plurality of rods having threaded ends receiving nutsfor attaching said end caps to said tubular members; e. a pair ofstabilizer plates supported by said plurality of rods; f. bulb socketsmounted on the opposite interior faces of said stabilizer plates forreceiving a fluorescent bulb; g. electrical wires interconnecting saidbulb sockets; h. a chassis mounted on said plurality of rods; and i. aballast and starter mounted on said chassis and electrically connectedwith said electrical wires for operating said fluorescent bulb.
 2. Atube light as defined in claim 1 further comprising: a. an electricalconnector extending through an opening in each of said end caps; and b.said electrical wires connected to said electrical connectors andarranged so as to permit electrically parallel circuit operation of saidtube light with other similarly connected tube lights.
 3. A tube lightas defined in claim 1 further comprising: a. a radio frequencyinterference shield surrounding said transparent tubular member; and b.said radio frequency interference shield being held in place by said endcaps.